Excavating tooth and base support therefor



P. V. LARSEN Jan. 5, 1960 EXCAVATING TOOTH AND BASE SUPPORT THEREFOR Filed April 21, 1958 4 Sheets-Sheet 1 lNVENTOR' lMW A TTO/PNEVS.

Jan. 5, 1960 P. v. LARSEN 2,919,506

EXCAVATING TOOTH AND BASE SUPPORT THEREFOR Filed April 21, 1958 4 Sheets-Sheet 2 lNVE/VTOR 044w fl bzhiaww a A TTORNEVS.

P. V. LARSEN EXCAVATING TOOTH AND BASE SUPPORT THEREFOR Jan. 5, 1960 4 Sheets-Sheet 4 Filed April 21, 1958 VENTOR M Wi /34w.

By ATTORNEYS.

rear end of the point and nose.

United States Patent EXCAVATING TOOTH AND BASE SUPPORT THEREFOR ,PaulV. Larsen, Portland, reg., assignor to-Electric Steel 1 Foundry Company, Portland, Oreg., a corporation of Oregon Application April 21, 1958, Serial No. 729,858

28 Claims. (Cl. 37-142) This invention relates to an excavating tooth. and base support therefor, and more particularly to replacement ,teeth and points adapted for use on power-driven excavating these elements. The nose may be the adapter nose,

or it may be the nose formed integrally with a base member suchv as the lip of a bucket or dipper, etc., and the socket element may be the cap portion of an adapter received upon the nose of the baseor it may be the tooth point carried by the nose of the adapter itself. For the purpose of simplicity in describing the invention, I will refer mainly to the nose carried by the adapter and to the tooth point carried thereby. In the type of adapter nose and point commonly employed today, the nose has angularly-related flat surfaces and these contact similar .surfaces in the tooth point.

While tooth designers have hoped to develop a tooth which might be held so tightly by mechanical means upon the adapter nose that the point could not move sidewise, this result has not been achieved, and further, in the operation of the tooth, wear occurs which increases the movement of the tooth point upon the adapter nose.

I have discovered that in the swinging movement of the tooth point upon the nose under impact with rocks, etc., the lateral swinging movement of the point, by reason of the flat angular contacting nose surfaces, pivots about one edge at the rear of the tooth point. Two surfaces such as are presented by the top and bottom surfaces of the nose in contact with mating surfaces in a tooth point, cannot swing laterally without changing the full bearing area on the two surfaces to a point contact at the opposite In other words, any pivotal movement sidewise of the tooth changes it from a full bearing area to a point contact, the point contact being at one back corner of the point opposite to the direction in which the tooth is moved. This point contact, by directing the full force of the impact thereon, causes excessive wear and greatly shortens the life of the tooth point.

A further phenomenon affecting the point wear of the tooth is that when the point tilts upon the nose at one rearcorner of the. point, the tooth point moves forward along the nose so that we have not only a lateral movement but also a longitudinal movement of the point.

specific points on which the heavy frictional stress is exerted, but also place stress upon the key or other fastening means employed to anchor the point and nose elements together. As an illustration, it is found that when the tooth point has been swung sidewise over the base approximately one-eighth of an inch, with the pivot point being at one rear corner of the point, the longitudinal movement at the apex is doubled to a one-fourth inch clearance at the apex.

If it were possible to provide a base or adapter nose with a tooth point or socket element carried thereby so that in the lateral swinging movement of the socket element there is provided a full bearing area, thus obviating point contact, it would be possible to increase the life of the toothgreatly and it might be possible that the socket element would in some instances last the life of the bucket or other supporting base member.

An object of the present invention is to provide a nose support and socket element in the nature of a point or cap or sleeve mounted on said nose whereby under impact the element may swing to a limited extent laterally while providing full bearing or surface contact between the parts throughout such lateral movement. Another object is to provide an excavating device in which cooperating nose and socket elements have surfaces which remain in contact during lateral movement of one of the members with respect to the other, while at the same time providing a sturdy interlock between the members. A still further object is to provide a combination of nose and socket elements united by keys or other means whereby the parts may swing relative to each other to a limited extent while at the same time providing wide areas of contact between the members during each portion of such travel so that a large bearing surface is provided between the members under heavy load and irrespective of'the relative position of the two members. Yet another object is to provide in excavating devices nose and socket elements wherein the nose is provided with a cone surface or other surface of revolution contacting a corresponding surface of the socket element, thus enabling the parts to move in an are relative to each other with the bearing surfaces of the two members substantially in full contact. Other specific objects and advantages will appear as the specification proceeds.

The invention is shown, in an illustrative embodiment, by the accompanying drawings, in which Figure 1 is a top plan view of a base, adapter, and tooth point structure embodying my invention; Fig. 2, a longitudinal sectional view, the section being taken as indicated at line 2-2 of Fig. 1; Fig. 3, a detail sectional view, the section being taken as indicated at line 3-3 of Fig. 2; Fig. 4, a side view in elevation of a cone element and tooth point element shown in engaging relation for'illustrating the operation of the structure shown in Figs. 1-3, inclusive; Fig. 5, a bottom plan view of the structure shown in Fig. 4; Fig. 6, a view similar to Fig. 4 but showing a single cone; Fig. 7, a perspective view of the cone and tooth point structure illustrated in Fig. 4, the cone and point elements being shown spaced apart; Fig. 8, a transverse sectional view showing a socket type tooth with eye-bolt means for securing a point within a socket member; Fig. 9, a sectional view in a plane transverse to the plane shown in Fig. 8; Fig. 10, a rear end view of the point shown in Figs. 8 and 9; Fig. 11, a sec tional view similar to Fig. 2 but showing an adapter nose having a single cone engaging the socket portion of the .point; and Fig. 12, a transverse sectional view, the section being taken as indicated at line 12-12 of Fig. 11.

In Figs. 1-3, inclusive, a specific embodiment of the inventionis set out by way of illustration. The base member A may be a part of a scarifier or dipper or bucket,

and may, of course, be formed in a variety of shapes orforrns. In the illustration given, A represents a base ex= 3 tension having therein a central opening receiving the shank of an adapter B. The adapter B carries a tooth point C.

The base A is provided with a pair of spaced nose portions which are enclosed within sockets 11 formed in the adapter B.

The adapter B has a rearwardly-extending shank portion 12 apertured to receive a key 13 which passes through a recess 14 in the upper portion of the base member A and a recess 15 in the lower portion of the base A. The key may be of any suitable form or shape. In the illustration given, the key is provided with a circular forward portion 16 and a circular rear portion 17, as shown best in Fig. 1.

The adapter B is provided at its forward end with a nose 18 which is shown in the shape of a cone segment having the curved top and bottom surfaces as indicated by the numerals 19 and 20. Such cone surfaces will be described in greater detail hereinafter. At the rear of the nose 18, the adapter B is provided with a guide projection 21 having a fiat bottom guide surface 22 and a similar guide surface 23 at its top. A locking member 24, having a corrugated forward surface, is provided with rearwardly-extending guide flanges 25 adapted to slidably engage the guide surfaces 22 and 23 of the projection 21. An elongated block of rubber 26 or other resilient material is interposed between the locking member 24 and the projection 21, and normally urges the member 24 for wardly into engagement with a key member 27 The nose 18 is provided with a vertical slot therethrough for receiving the members 24, 26 and 27.

The key 27 has a plurality of corrugations which engage the forwardly-extending corrugations on the locking member 24, and this structure has the important advantage of permitting the key to be readily inserted and removed by driving the same into and out of position, while at the same time remaining sturdily in position during the operation of the parts. The multiple corrugations provide interlocking surfaces which are effective in retaining the parts in interconnected relation during heavy usage but, at the same time, when the key is driven into position and when later it is driven out of position by a tool inserted through the openings in the lower portion of the point, the corrugated mating surfaces permit ready insertion and removal.

The tooth point C may be of any suitable form or shape. In the illustration given, the point comprises a top heavy spike portion 23 and a lower web portion 29 connected by side webs 30. The point or socket element C provides on its interior a socket 31 conforming in shape substantially to the shape of the nose 18. The forward end 32 of the socket is arcuate and conforms substantially in shape to the forward curved contour 33 of the nose 18.

The tooth point C is provided at its rear with spaced, rearwardly-extending tongues received within recesses in the adapter B. The top tongue or strap 34 is received within a recess 35, shown best in Fig. 2, while the rearwardly-extending tongue 36 at the bottom of the member C is received within the recess 37 at the bottom of the adapter B. The rear side wall edges of the tooth point are preferably recessed to form forwardly-extending concave edges, as indicated by dotted lines at 38 in Fig. 2.

While in the drawings the nose 18 is rather snugly received within the socket 31 of the point C, it will be understood that in actual practice there is play between the parts and upon use of the tool and heavy wear, the spacing between the parts increases and the point C, when struck at one side near its forward end with rocks which are wedging between the teeth, swings laterally. It is a purpose of the cooperating nose and socket structure shown herein to support fully the point upon the nose in such lateral swinging movements so that point contact or point wear is substantially obviated. It is believed that the operation of the structure can be best described lay-referring to the illustrations set out in Figs. 4 to 7,

inclusive. In Figs. 4, 5 and 7, a double cone member 40 is shown, with the forward end of the cone received within a point C The sides of the member C are cut away. The socket 41 provided within the member C fits the cone contour of the member 40 so that the member C can be rotated around the member 40 on an axis which is at the center line of the cone. From this illustration, it will be noted that the cone surfaces and the cooperating or fitting surfaces of member C remain in full bearing contact as the member C is rotated about the member 40 or as the member 40 is rotated within the socket 41 of member C In Fig. 7, an imaginary line 42 is drawn to indicate how the cone area would be sectioned to provide the nose area 43 adapted for the forming of the nose 18, as shown in Fig. 2. It will be observed that the imaginary line 42 extends to the vertical center axis of the cone, and when a key member is extended through the cone so that its rear edge is aligned with the center of the cone, the member 43 could rotate within the socket 41 of the member C, just as such rotation is accomplished in the structure illustrated in Fig. 2 where the key 27 forms a vertical axis at the rear center of the cone segment. With this structure, there is no point contact, but, instead, the cone surfaces of the portion 43 remain in full engagement with the bearing surfaces within member C irrespective of the position to which the member C is swung.

In the structures described, both in Figs. 1-3 and in Figs. 4, 5 and 7, the nose structure is in the shape of a double cone, and one advantage of this structure is that the socket element or tooth point is reversible. Where reversibility is not required, a single cone form of nose may be employed, and such a structure is illustrated in Fig. 6. The cone member 44 has a straight side 45 engaging the straight upper surface 46 of the upper socket wall of point C while the lower cone surface 47 engages a corresponding concave surface within the lower portion 48 of the point C While in the illustrations given I have shown cone surfaces having the contour illustrated, it will be understood that the contour may vary widely. Instead of a straight line cone, as illustrated, the outer cone surface may be curved or may be formed of curved and straight segments. For example, the cone may be regarded as a surface of revolution formed by revolving about a single principal axis two angularly-related surfaces (curved or straight or both), and the corresponding socket element should provide corresponding support bearing surfaces which will remain in contact during relative movement of the members. The nose and socket elements should be in telescoping relation and united by a pivot member providing a single axis about which said members may move or rotate relative to each other, each of the members having two angularly-related bearing surfaces in contact throughout the major portion of their area. These surfaces are surfaces of revolution generated by revolving two nonparallel and spacedapart imaginary lines about the single axis whereby the nose and socket members may rotate relative to each other with their bearing surfaces substantially in full contact.

Instead of a cone surface or double cone surface, one may employ similar or equivalent socket and nose contours which will permit relative rotation of the two parts while still maintaining their bearing surfaces in substantially full contact during any "stage of such relative movement. The cone structures, however, provide the advantage of simplicity, smooth operation, and sturdiness, while also the structure requires a swinging movement rather than a sidewise lateral movement. When rocks wedge between teeth in the normal operation of the excavating device, a bodily movement in translation laterally of the nose would tend to damage the teeth and other structure and further would be less effective in releasing the rocks, etc. With the cone structure shown, the point is cone.

restrained from a body movement in translation laterally ofthe nose by the cone surfaces, while at the same time the cone surfaces permit swinging movement on the center axisof the cone.

The nose structure 18 has been described in detail so as to illustrate the double or single cone relationship of the adapter nose to the tooth point. I now wish to refer to the nose members 10 carried by the base A and i"eceived within sockets 11 of the adapter B. The nose niembers 10 are also preferably formed as a part of a. continuous cone with an inner segment removed to receive the shank portion ofthe adapter B. By shaping the nose inembersltl as portions of a'continuous cone-of the type illustrated in Figs. 4, and 7 and by shaping the sockets 11 in the adapter B so as to provide contacting surfaces receiving the cone segments 10, a swinging movement of the adapter B about the key 13 provides the same fullbearing support heretofore described in connection with the no'se18. In the latter operation, since the key 13 'has a circular rear edge portion 17, the center of ro- ;t-ation =would be-about thecenter 17a'of'the key portion :17 and the axis ofgeneration of the cone segments iscalso' located at the center 17a of the key portion.

From the foregoing, it will be observed that the nose -'rnay be=inone or several parts 'and may be formed in double or single cone shapes, with straight or curved lines, mating with corresponding sockets surfaces in the other members so as to provide the full bearing support irrespective of the position to which the relative members may be'swung under operating conditions. As stated hereinabove, the double cone form of nose permits the tooth to bereversed in position for longer wear and more effective use, and the single cone structure may be employed where reversibility is not required.

The key 17 rotates on the center of the radius 17a,

which is the apex of the cone. The key is at a right angle to a horizontal plane through the center of the double In'the case of a single cone, a key may be located at right angles to the center line of the top surface of the tooth C, and this necessitates a single cone. The key will lock if not rotated on the single or double cone center.

In the structure shown in Figs. 8, 9 and 10, a socket holder'member 49 receives a point 50. This type of 'structure is usually referred to as a socket type tooth.

The point 50 is provided at its rear with a central opening-51 adapted to receive an eye-bolt 52 and with a transverse opening 53 adapted to receive the eye-bolt pin 54. The threaded rear end 55 of the eye-bolt receives a nut 56 adapted to bear against the web bridge -member57 of the socket member 49. Since the socket type of tooth equipped with eye-bolts is a well known structure, a description ingreater detail is believed unnecessary.

In the socket type tooth structure shown in Figs. 8-10,

"inclusive, the point 50 has a rearwardly-extending nose portion 58 having an upper concave surface 59 and a lower concave surface 60. These concave surfaces may be described as an inverted conical bearing, and are thereverse of the nose surfaces 19 and 20 shown in Fig. 3. The walls of the socket member 49 in contact those shown in Fig. 3 in that the bearing surfaces of the nose 58 are concave rather than convex, and the surfaces ofthe holder member fitting such nose surfaces are convex conical surfaces.

In the structure shown in Fig. 8, the pivot point is at 61, namely, at the forward and center face of the nut 56.

It will be understood that there are many forms of tooth points and sockets or holders for the teeth, and that in each of such structures cone bearings may be provided which will enable the members to move relatively due to lateral stresses about a key or a central pivot point to accomplish the purposes of the invention herein, and I shall not attempt to set out the many different forms of teeth and holder or adapter structures which may be so employed.

It will also be understood that the nose 18 may be provided directly by the base A and without any interposed adapter or like member.

In the modification shown in Figs. 11 and 12, the nose 18a of the adapter B provides a single cone having its top surface 19a lying in a generally straight line, as illustrated best in Fig. 12. The structure is otherwise the same as shown in Fig. 2 with the members C and B connected by a key 27a engaging the retainer member 24a and being held in engaging relation by the resilient compressed pad 2611.

Operation In the operation shown in the illustrative models in Figs. 4-7, inclusive, the cone member is firmly received within socket recesses in the point C or C and may rotate therein with the bearing surfaces of the two parts in full contact.

In the preferred structure shown in Figs. 13, inclusive, the nose is fully enclosed within a socket and a section of the cone forms the nose. When the adapter B moves under stress imposed upon it laterally about the pivot point 17a, the cone portions 10 of the base A remain in full contact with the corresponding concave socket portions 11 of the adapter B. When the point C is moved laterally by the wedging of rocks between it and the adjacent tooth, the point swings along the cone surfaces of the nose 18, with the bearing surfaces of the two members in full contact.

When the point is to be assembled with the adapter, as illustrated in Fig. 2, the key 27 is driven downwardly to the position shown in Fig. 2, with the corrugated rear surface thereof engaging the corrugated forward surface of the locking member 24, and in this action the member 24 slides rearwardly in guided relation with the projection 21 and compressing the resilient block 26. For removing the key, a tool element may be placed against the bottom of the key 27 and the key driven upwardly and out of the position shown so as to free the point C from the adapter nose.

Referring more particularly to the structure shown in Fig. l, the curved forward edge 33 of the nose permits relative movement of the nose and point, with little wear along the sides of the point. With the structures heretofore employed, in which square nose ends are provided, the relatively swinging movement causes point contact at the forward side edges of the nose, tendin to cut through the side walls of the point during heavy operations. In the present structure, the rounded or arc-like forward structure of the nose, in cooperation with the rounded pocket of the point C, enables relative movement of the parts to take place under heavy stress without injury to the point side walls.

While an important advantage of the present application lies in the full cone bearing area so that in any position of the parts there is provided a substantially full bearing surface to carry the stress, it will be understood that much of the advantage of the present invention can also be utilized where all of the bearing surfaces are not constantly in full contact but where a major portion of such surfaces are in contact for the bearing of the loads.

While, in the foregoing specification, I have shown the conical surface employed on the nose of a specific form of tooth, it will be understood that the surface may be employed with any type or kind of a tooth or point where a nose is employed and a point or socket member is held upon the nose.

7 The cooperative action of the nose and socket element prevents lateral shifting bodily of the element upon the nose in translation but permits swinging movement of the element, as under wedging impact of rocks, etc., while the bearing surfaces of the two members remain in contact or in contact for the major portion of their working area. This structure avoids point contact and wear, and by maintaining the bearing surfaces in contact over wide areas during the movements of the parts, a long wearing point or socket element is provided.

As above stated, the conical bearing surfaces permit pivotal movement but resist lateral movement regardless as to whether or not there are confining side walls, and therefore the fit of the side walls and whether the side walls fit tightly or loosely are relatively unimportant.

In the specific structure shown in Figs. 8-10 inclusive, the point 50 is drawn into position with its nose portion received within the socket of the member 49, the eye-bolt 52, in coaction with the nut 56, serving to lock the point 50 within the holder member 49. The concave surfaces 59 and 60 fitting within the corresponding convex conical surfaces of the holder 48 may rotate upon the vertical axis 61 when play occurs between the fitting parts, but in such movement the full bearing of the contacting surfaces is utilized irrespective of the position to which the parts move in such rotation. The operation is the same as that heretofore described in connection with the structures shown in Figs. 1, 2 and 3, notwithstanding the fact that the conical contacting surfaces described in Figs. 8-10 inclusive are the reverse of those shown in Fig. 3. In other words, the nose 18 in Fig. 3 has conical surfaces mating with concave surfaces in the member 28, while in the structure shown in Figs. 8-10 inclusive the nose 58 has concave surfaces mating with corresponding convex conical surfaces provided by the holder member 49.

While, in the foregoing specification, I have set forth a specific structure in considerable detail for the purpose of illustrating an embodiment of the invention, it will be understood that such details of structure may be varied widely by those skilled in the art without departing from the spirit of my invention.

1 claim:

1. A supporting structure for an excavating tooth, and the like, subject to stresses tending to produce sideways movement, comprising a tapered nose member and a socket member receiving said nose member, said socket member having confronting upper and lower interior bearing surfaces fitting corresponding upper and lower exterior bearing surfaces on said nose member, said hearing surfaces being surfaces of revolution having a common axis extending vertically of said nose, and means on said axis interconnecting said members for limited relative rotation of one of said members in a sideways direction about said axis, whereby said' bearing surfaces remain in fitting contact during said sideways movement of one of said members.

2. A structure as defined in claim 1 wherein said socket member is a tooth point and said nose member is a supporting element for said tooth point.

3. A supporting structure for an excavating tooth, and the like, subject to stresses tending to produce sideways movement, comprising a tapered nose member having upper and lower exterior bearing surfaces converging toward the end of the nose member, and a socket member receiving said nose member and having corresponding confronting upper and lower interior bearing surfaces fitting said nose surfaces, said bearing surfaces being surfaces of revolution generated by converging lines revolved about a substantially vertical axis through said members at a distance from said end of the nose and means interconnecting said members for relative rotative movement of one of said members about said axis, whereby said bearing surfaces remain in fitting contact during such movement.

4. In an excavating device, a supporting nose element and a socket element receiving said nose, said nose element and said socket element being mounted for limited relative rotation, a key member interconnecting said nose element to said socket element and providing a single vertical axis about which one of said elements may rotate, said elements each having two angularly-related bearing surfaces in Contact throughout the major portion of their area, said surfaces being surfaces of revolution generated by revolving two non-parallel imaginary lines about said single axis, whereby said elements are interconnected for relative rotation with said bearing surfaces remaining in fitting contact about said single axis.

5. The structure of claim 4, in which said nose has a cone surface.

6. The structure of claim 4, in which said nose has double cone surfaces.

7. The structure of claim 4, in which said elements are connected by said key having its rear portion aligned generally with the center of the axis of revolution.

8. A replaceable excavating tooth point, comprising a spike portion integral with and projecting forwardly from a supporting portion, said supporting portion having top and bottom bearing surfaces adapted to engage longitudinally-extending top and bottom bearing surfaces on a tooth point support, said bearing surfaces on said tooth point being generally convergent in a direction longitudinally of the tooth point, and said bearing surfaces being surfaces of revolution having a common axis of generation adjacent the rear extremity of said supporting portion and extending in an approximately vertical direction with respect to said top and bottom surfaces.

9. A tooth point as defined in claim 8, said supporting portion further including opposite side surfaces extending between and interconnecting said top and bottom bearing surfaces.

10. A tooth point as defined in claim 9, said supporting portion further including means for connecting the tooth point with its support on said axis of generation of said top and bottom bearing surfaces.

11. A tooth point as defined in claim 10, said supporting portion comprising a socket in which said top and bottom bearing surfaces and said side surfaces are in ten'or surfaces in the socket to fit a nose-shaped support.

12. A tooth point as defined in claim 11, said connecting means including a vertical key passage through top and bottom walls of the socket.

13. A tooth point as defined in claim 10, said supporting portion comprising a nose in which said top and bottom bearing surfaces and said side surfaces are exterior surfaces to fit a socket-shaped support.

14. A tooth point as defined in claim 13, said connecting means comprising a tension bolt extending rearwardly from said supporting portion and intersecting said axis of generation.

15. An adapter for supporting a replaceable excavating tooth point projecting forwardly therefrom, said adapter having top and bottom bearing surfaces adapted to engage longitudinally-extending top and bottom bearing surfaces on the tooth point, said bearing surfaces being generally convergent in their longitudinal direction, said bearing surfaces being surfaces of revolution having a common axis of generation adjacent a rearward portion thereof, said axis of generation extending in an approximately vertical direction with respect to said top and bottom surfaces.

16. An adapter as defined in claim 15, and further including opposite side surfaces extending between and interconnecting said top and bottom bearing surfaces.

17. An adapter as defined in claim 16, and further including means for connecting the tooth point therewith on said axis of generation of said top and bottom bearing surfaces.

18. An adapter as defined in claim 17, said adapter having a forwardly-projecting nose portion with exterior surfaces forming said top and bottom bearing surfaces and said opposite side surfaces.

19. An adapteras defined in claim 18, said connecting means including a vertical key passage through said nose portion.

20. A tooth point for an excavating tooth subject to stresses tending to produce lateral movement in a given plane, comprising a point having a support portion adapted to fit a support member for movement in said plane and having upper and lower longitudinally extending bearing surfaces generally convergent in a direction longitudinally of the tooth point, at least one of said bearing surfaces being a surface of revolution having an axis of generation perpendicular to said plane and being interrupted and flanked by side edges of said support portion.

21. An adapter for supporting a replaceable excavating tooth point projecting forwardly therefrom, said adapter having top and bottom bearing surfaces adapted to engage longitudinally-extending top and bottom hearing surfaces on the tooth point, said bearing surfaces being generally convergent in their longitudinal direction, at least one of said bearing surfaces being a surface of revolution having a common axis of generation adjacent a rearward portion thereof, said axis of generation extending in an approximately vertical direction with respect to said top and bottom surfaces.

22. An adapter as defined in claim 21, said adapter having a forwardly-projecting socket portion with interior surfaces forming said top and bottom bearing surfaces and said opposite side surfaces.

23. An adapter as defined in claim 22, and further including means for connecting the tooth point therewith on said axis of generation of said one bearing surface, said connecting means including an abutment surface in the adapter adjacent the rear end of said socket.

24. A supporting structure for an excavating tooth and the like, subject to stresses tending to produce sideways movement, comprising a tapered nose member and a socket member receiving said nose member, said socket member having confronting upper and lower interior bearing surfaces fitting corresponding upper and lower exterior bearing surfaces on said nose member, at least two of the corresponding bearing surfaces of said nose member and said socket member being surfaces of revolution having a common axis extending vertically of said nose, and means on said axis interconnecting said members for limiting relative rotation of one of said members in a sideways direction about said axis, whereby, said bearing surfaces of revolution remain in fitting contact during said sideways movement of one of said members.

25. A structure as defined in claim 24 wherein said nose member is a tooth point and said socket member is a supporting element for said tooth point.

26. A supporting structure for an excavating tooth, and the like, subject to stresses tending to produce sideways movement, comprising a longitudinally tapered nose member having an upwardly facing top exterior bearing surface and a downwardly facing bottom exterior hear ing surface, said top and bottom bearing surfaces converging toward the end of said nose member, and a socket member receiving said nose member and having corresponding confronting top and bottom interior bearing surfaces fitting said nose surfaces, said bearing surfaces being surfaces of revolution having a common axis of generation at a distance from said end of the nose and extending in an approximately vertical direction with respect to said top and bottom surfaces, and means interconnecting said nose and socket members for limited relative rotative movement of one of said members about said axis with said bearing surfaces in fitting contact during such movement.

27. A supporting structure as defined in claim 26 in which said nose member comprises spaced-apart nose segments having top bearing surfaces lying in a common surface of revolution and having bottom bearing surfaces lying in a common surface of revolution.

28. A tooth point for an excavating tooth subject to stresses tending to produce lateral movement in a given plane, comprising a point having a support portion adapted to fit a support member for movement in said plane and provided with a pair of upper and lower converging and longitudinally-extending bearing surfaces, at least one of said bearing surfaces being a surface of revolution having an axis of generation perpendicular to said plane, said surfaces being interrupted and flanked by side edges of said support portion, and means provided by said point for receiving a retaining pin extending generally parallel to said axis of generation.

References Cited in the file of this patent UNITED STATES PATENTSv 802,178 Treacy Oct. 17, 1905 1,799,929 Rauch Apr. 7, 1931 1,834,514 Brune Dec. 1, 1931 1,890,981 Finkl Dec. 13, 1932 1,918,841 Finkl July 18, 1933 2,113,420 Younie Apr. 5, 1938 2,145,663 Reynolds Jan. 31, 1939 2,666,272 Everett Jan. 19, 1954 FOREIGN PATENTS 475,297 Canada July 17, 1951 

